Steam generator



Ot. 3, 1950 J. 1. CANTRELL STEAM GENERATGR Filed Jan. 4, 1949 5 4- mL M1 en Nc...L a

.m w.. ,L W 2 mNY B HGURE 1 FIGURE 5j v /56 C wf Patented Oct. 3, 1.950

UNITED STATES PATENT OFFICE 2,524,307 STEAM GENERATOR John IsomCantrell, Mobile, Ala. Application January 4, 1949, Serial No. 69,223

(Cl. 21S- 38) 1 Claim.

The present invention relates to improvements in steam generators andhas for an object to provide an electrically heated steam generator inwhich a high thermal efficiency is secured by an exceedingly simpleconstruction.

Another object of the invention is to so mount the electric heating unitthat it may be readily attached and removed from the water space of theboiler.

With the foregoing and other objects in View, the invention will be morefully described hereinafter and more particularly pointed out in theappended Claim.

In the drawings, in which like parts are denoted by the same referencecharacters throughout the several views,

Figure 1 is a side elevational view of an improved steam generator orboiler constructed in accordance with the present invention with partsbroken away and parts shown in section;

Figure 2 is an end elevational view of the same;

Figure 3 is a sectional view, taken on a greatly magnified scale, ol oneof the two electrical terminals employed for suspending the resistancecoil across the steam generator and to receive the external circuitconnections; and

Figure 4 is a side elevational view taken on the same scale and showingthe plug portion of such terminal and its connections.

Referring more particularly to the drawings, I2 designates a resistanceco-il which is stretched across the lower portion of the water space ofthe steam generator I1 which may be in the form of a cylindrical boiler.

The external electric circuit is indicated at I3 and I3A and connectsthe resistance coil I2 with any outside source of electric currentwhereby the coil I2 becomes energized. The external circuit may be underthe control of a manual switch if desired.

The terminals carrying the resistance coil I2 in the cylindrical boileror steam generator I1 are specially constructed. The terminals I4 and I5are substantially identical, and one such terminal I4 is shown inFigures 3 and 4 to comprise a casing block 56 Welded or otherwisesecured to the end head of the steam generator I'I and having aninternal bore 51 and a rediced externally threaded projecting neck 58 towhich is threadedly secured a cap 59 to enable the same to be removed.The cap is formed With a central opening 60.

The cap holds in place the head 6I of a brass plug 29 having a centralopening for receiving therethrough the mica or other non-conductingsleeve 30. Such sleeve is pierced centrally to receive a center wire orrod 3l having the terminal eyes 62 and 63 to receive the externalcircuit wire I3 and the inner end of the resistance coil l2respectively. The center rod or wire 3| is composed of copper or otherconducting material.

In operation. the passage of electric current through the resistancecoil I2 causes the coil to become heated in a well-known manner and toconsequently heat the body of water surrounding the same to eventuallyconvert such water into steam which rises to the steam space of thegenerator I'I and passes therefrom through the pipe It and into thesteam dome or valve chest of a steam engine.

VBy unscrewing the caps 59 at both ends the entire resistance wire I2and its plugs may be withdrawn through the opening 5'! at one end of theboiler. For the purpose of unscrewng the cap 59, it will be understoodthat the opening 6G is wider than the eye 62.

In this way the resistance wire may be introduced and removed in a verysimple operation.

'While I have disclosed herein the best form of the invention known tome at the present time, I desire it to be understood that I reserve theright to make changes and modifications in the herein describedembodiment of the invention provided such changes fall within the scopeof the following claim.

What I claim is A steam generator comprising a boiler having opposed endwalls rand a water space, said end walls having alined openings, anelectric resistance heating coil stretched across the lower portion ofthe water space within the boiler and being of a diameter less than thediameter of the end wall openings to permit passing of the coil throughsuch openings, casing blocks secured to the outside faces of said endwalls and having internal through bores of substantially the samediameter as the openings and registering with such openings, said blockshaving threaded necks in their outer portions, plugs slidable into andout of said bores and having heads wider than the bores for encounteringthe outer ends of the necks to prevent the plugs being drawn through thebores into the boiler by the weight and tension of the resistance coil,non-conducting sleeves iitted through said plugs, conductor rods ttedthrough said sleeves and having internal connections for electricalconnection to said resistance coil and for the mechanical support of thecoil in its stretched condition across the water space and also havingexternal connections for including in an external electric circuit, andthreaded caps removably mounted to said threaded necks and having outerend discs engaging said heads to hold the heads against the necks, saiddiscs having openings wider than said connections.

JOHN ISOM CANTRELL,

REFERENCES CITED The following references are of record in the

